One method of treating waste water is by use of a septic system. The prior art septic system shown in FIG. 1 may include a tank 10 that may comprise a single chamber 11. The tank may be capped with a lid 12 that has at least one access port 13 formed in it. The access port or ports 13 may be located proximate to an end of the lid 12 or may be centered in the lid 12 as desired. In FIG. 1, the access port 13 is shown as located adjacent one end of the lid 12. The tank 10 may be buried in the ground 14.
Access to the septic tank 10 may be available through a septic tank cover 16 which may allow access to the septic tank through a conduit or septic tank riser 17 that may be mated to the access port 13 in the lid 12 of the septic tank 10.
Two kinds of septic systems are currently in use: in one, the effluent flows out of the tank 10 under the influence of gravity. Alternatively, as shown in FIG. 1, an electric pump 18 is used to pump the effluent up the discharge pipe 19 and out into the drain field (not shown).
As building codes and the like may require that the pump 18 be elevated above the bottom of the tank 10, the current practice is to position a concrete paver or block 21 having a thickness, in some cases, of 4 inches (10 cm) or greater on the bottom of the tank 10, and position the pump 18 on top of the block 21. Unfortunately, the the block 21 is frequently mispositioned in the tank 10, and correcting the positioning of the block 21 from the surface through the septic tank riser 17 can be difficult or impossible. If one or more of the legs of the pump are not seated on the paver or block 21, the torque of the pump 18 starting up and shutting down may apply a tortional force to the discharge pipe 19 that may ultimately lead to its structural failure.
In addition, particulate matter may settle in the tank to form a layer of sludge 22, the upper surface of which slopes generally up and away from the location of the pump 18. When excessive sludge has accumulated, it may be necessary to pump the tank 10 out.